German Engineer’s office Reinhard Beck has created an online Pentomino puzzle version named after named the American mathematician Salomon Golomb.

You can solve four different rectangles with the 12 pieces, which have an area of 60 squares. There are many different arrangements to get this rectangles:
rectangle 3×20 – 2 solutions
rectangle 4×15 – 368 solutions start show
rectangle 5×12 – 1010 solutions start show
rectangle 6×10 – 2339 solutions start show

Game instructions : Use mouse down to drag, shift-click to rotate and ctrl-click to mirror a piece. If you like this puzzle game you can also buy the real version of Katamino. Happy Puzzling!